The present invention relates generally to office machines, including electrostatographic reproduction machines, that have blowers, and more particularly, concerns such a machine having a blower noise reducing device.
Office machines such as computers, other data storage and processing devices, and image reproduction machines like copiers, faxes, and printers, typically include a machine frame, operating components within the frame, and a blower for either removing heat or dust particles and dirt from the machine. For example, in a typical toner image reproduction machine, for example an electrostatographic printing process machine, a photoconductive member is charged to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoconductive member is exposed to a light image of an original document being reproduced. Exposure of the charged photoconductive member selectively dissipates the charges thereon in the irradiated areas. This records an electrostatic latent image on the photoconductive member corresponding to the informational areas contained within the original document.
After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by bringing a developer material, container toner particles, into contact therewith. Generally, the developer material comprises toner particles adhering triboelectrically to carrier granules. The toner particles are attracted from the carrier granules to the latent image forming a toner powder image on the photoconductive member. The toner powder image is then transferred from the photoconductive member to a copy sheet. The toner particles are heated to permanently affix the powder image to the copy sheet.
The foregoing generally describes a typical black and white electrostatographic printing machine. With the advent of multicolor electrophotography, it is desirable to use an architecture which comprises a plurality of image forming stations. One example of the plural image forming station architecture utilizes an image-on-image (IOI) system in which the photoreceptive member is recharged, re-imaged and developed for each color separation. This charging, imaging, developing and recharging, re-imaging and developing, all followed by transfer to paper, is done in a single revolution of the photoreceptor in so-called single pass machines, while multi-pass architectures form each color separation with a single charge, image and develop, with separate transfer operations for each color.
Dust and the toner particles used in such machines for image development usually are in the form of a fine black powder which tends to escape and deposit on various components of the machine, with deleterious effect. In addition, such machines also include heat generating components such as a fuser apparatus. In general most office machines such as computers and the like include heat generating components or components that tend to heat up, and thus requiring cooling. Typically, the solution to both dust and heat problems is to include an air blower with the machine.
Such air blowers conventionally have noise generating components such as rotating impellers or defusers which having complementary surfaces and configurations within a housing chamber. There is, therefore, a need for office machines that include noise reducing devices within such air blowers.
In accordance with one aspect of the present invention, there is provided an office machine including a machine frame defining an operating environment, operating components mounted within the frame and requiring environmental conditioning such as cooling and cleaning, and an air blower for conditioning the operating environment within the frame. The air blower includes a housing having a housing wall defining an air path and an air discharge opening, a discharge nozzle, mounted over the discharge opening for directing air being discharged away from the housing, a pinch point formed between the housing wall and the discharge nozzle at the discharge opening, an air moving assembly including a rotatable impeller mounted within the housing for drawing air into the air path, and a blower noise reducing device on the pinch point for minimizing air stagnation at the pinch point. The blower noise reducing device includes a first surface for protruding into the air path, and a second surface for protruding into the discharge nozzle, for minimizing air stagnation within the air path and within the discharge nozzle, thereby reducing bower noise.